1. Field of the Invention
The present invention relates to a medication infusion deice, and more particularly, concerns a syringe infusion pump intended for the intravenous administration of medications.
2. Description of the Prior Art
Hospitals typically use intravenous (IV) administration sets to deliver liquids to patients. When the patient needs a drug, such as an antibiotic, it has been standard practice, until recently, to deliver such a drug by a "piggy-back" drip into the primary infusion line. Within the last several years, however, the procedure for delivering many drugs to patients on IV therapy has been changing. Mechanically driven syringes, also known as syringe infusion pumps, are now being used to handle the administration of drugs and similar medications.
Presently available syringe pumps for IV use are designed to operate at a constant speed or at a number of manually set, constant speeds. Once the syringe is positioned on the syringe pump, the syringe drive mechanism engages the plunger of the syringe and pushes the plunger at a constant speed into the syringe barrel so that the liquid contents are delivered to the patient over a fixed period of time. The time in which the medication is delivered to the patient is a function of the volume of fluid in the syringe. In order to meet the wide variation in syringe barrel dimensions for the different size syringes used in hospitals, it is presently necessary to have several different syringe pumps. Irrespective of the different syringe pumps for different size syringes, the syringe pumps remain constant speed devices.
When a drug is to be delivered to a hospital patient, the physician typically prescribes that a certain amount of the drug, by weight, be delivered to the patient over a period of time, usually in minutes. The hospital pharmacist usually must dilute the prescribed drug so that it may be delivered by use of a syringe pump. For presently available syringe pumps, however, which operate at constant speed, the pharmacist must calculate the volume of the diluted drug in order to be able to deliver that drug over the prescribed period of time. In many circumstances, the drug dilution calculated and prepared by the pharmacist is not the same drug dilution recommended by the drug manufacturer. As a result, drug dilutions, different from the recommended amount, may cause difficulties for fluid restricted patients or added complications occasioned by excessive drug concentrations. Accordingly, there is a present need to provide a syringe infusion device, for IV purposes, which may accommodate different size syringes and operate at different speeds so that drugs and medications may be delivered more conveniently and straightforwardly to the patient.